I have a 2000 dodge dakota 4.7L, AT that has an overfueling issue. I had a programmer on it, when i took it off the the truck started running rough. I replaced the upstream O2 sensor. The local dealer put it on the scanner for me to make sure that was the only problem. It worked for about 2 or 3 weeks then it started acting up again and i replaced the o2 sensor again under warrenty. This happened 3 times total. After the 3rd the dealership then took it upon them selfs to scan the truck, then 3rd time of replacing the o2 sensor they had started pulling the P0171-1/1 FUEL SYSTEM LEAN code. I got the print out sheet with all of the possible cause of the problem and with out spending outragous amounts of money their is no easy way to find out the problem.